The United States held Cristiano Ronaldo silent for 94 minutes and 30 seconds. But the Real Madrid winger needed only half a minute of magic to draw Portugal level, in turn denying the U.S. a spot in the knockout stages and salvaging the Seleccao's hopes of advancing.

That's how small the margins of error can be in a tournament of this scale. You take your eyes off the ball—quite literally—for a moment, and all of a sudden, your goalkeeper is picking the ball out of the back of the net.

The group stage will kick off its third round of matches on Monday with Group A and Group B action. With the way that the 2014 World Cup has unfolded so far, expect a few matches to go right to the final whistle.

2014 World Cup Tables

Team

P

W

D

L

GD

Pts.

Group A

Brazil

2

1

1

0

2

4

Mexico

2

1

1

0

1

4

Croatia

2

1

0

1

2

3

Cameroon

2

0

0

2

-5

0

Group B

Netherlands

2

2

0

0

5

6

Chile

2

2

0

0

4

6

Australia

2

0

0

2

-3

0

Spain

2

0

0

2

-6

0

Group C

Colombia

2

2

0

0

4

6

Ivory Coast

2

1

0

1

0

3

Japan

2

0

1

1

-1

1

Greece

2

0

1

1

-3

1

Group D

Costa Rica

2

2

0

0

3

6

Italy

2

1

0

1

0

3

Uruguay

2

1

0

1

-1

3

England

2

0

0

2

-2

0

Group E

France

2

2

0

0

6

6

Ecuador

2

1

0

1

0

3

Switzerland

2

1

0

1

-2

3

Honduras

2

0

0

2

-4

0

Group F

Argentina

2

2

0

0

2

6

Nigeria

2

1

1

0

1

4

Iran

2

0

1

1

-1

1

Bosnia-Herzegovina

2

0

0

2

-2

0

Group G

Germany

2

1

1

0

4

4

United States

2

1

1

0

1

4

Ghana

2

0

1

1

-1

1

Portugal

2

0

1

1

-4

1

Group H

Belgium

2

2

0

0

2

6

Algeria

2

1

0

1

1

3

Russia

2

0

1

1

-1

1

South Korea

2

0

1

1

-2

1

FIFA.com

Group A

Brazil, Croatia

Clive Brunskill/Getty Images

Brazil aren't mathematically through to the round of 16, but all they need is a draw against Cameroon and they'll be good. The Indomitable Lions have been one of the worst teams of the tournament, so it would be a shock if the hosts slip to third in Group A.

The real question is whether Croatia or Mexico will be joining Brazil.

Most predicted that their match on Monday would determine second place in the group, and that's exactly how it's unfolded.

Croatia coach Niko Kovac is trying his best to gain a mental edge ahead of the match, per Goal's Luis Herrera:

It wouldn’t be a failure not proceeding to the round of 16, but I’m not even thinking about that. We will enjoy or football tomorrow. Mexico have played very well since Miguel Herrera took charge, but we have a formula for them, although I’m not going to reveal it yet. (Guillermo) Ochoa is a great goalkeeper, but we have good forwards who will be a menace for him. If anyone have their knees shaking, it's Mexico.

Although El Tri will likely be playing for the draw, Croatia have more than enough in the attack to at least go a goal ahead. That 4-0 drubbing of Cameroon illustrated how good the Vatreni can be going forward. Alex Song's red card obviously helped, but don't forget that Croatia already had a 1-0 lead up to that point.

StipePletikosa is a bit of a worry in goal, but as long as Croatia can keep Mexico on the back foot, the risk that he has a howler should be mitigated.

Group B

Chile, Netherlands

Paul Gilham/Getty Images

Both Chile and the Netherlands are already through. Their match on Monday will determine the order of finish in the group.

Bruno Martins Indi will miss the fixture after getting concussed against Australia last week, per Goal's Stefan Coerts:

#NED defender Bruno Martins Indi has picked up a concussion against #AUS and is expected to miss the match versus #CHI. #WorldCup

Without Martins Indi, Louis van Gaal may have to go with a 4-3-3 formation, which leaves the back four a little more exposed. Eduardo Vargas and Alexis Sanchez have speed in abundance, so Daley Blind could really have trouble if he's deployed at left-back.

An even bigger problem for the Netherlands is that Chile look to have found their form against Spain:

With wins over Greece and Ivory Coast, Colombia are through to the next round. They should be able to remain top of Group C after their match against a Japan side suffering a power outage at the moment.

That leaves Ivory Coast and Greece.

Les Elephants will likely remain somewhat defensive because a draw almost certainly means they're through. Greece don't offer much in the attack, either, so they may have a hard time finding the breakthrough.

In the event the Greeks go down, that's all she wrote. KostasMitroglou was the one player who could bring a different dimension to the attack, but following his failures at Fulham, the free-scoring Olympiacos striker is nowhere to be found.

Group D

Costa Rica, Italy

With six points from three matches, Costa Rica are through. More than likely, they'll also finish top of Group D. England's attack will struggle against what's been Los Ticos' brick wall at the back. It will be interesting to see if Roy Hodgson opts for a more direct game with Rickie Lambert up front.

Uruguay and Italy are battling for the final spot.

Although a healthy Luis Suarez takes Uruguay to a different level, Cesare Prandelli should learn from his tactical failings against Costa Rica. Leaving Mario Balotelli up by himself was a mistake against a team. The Azzurri's long balls over the top did more harm than good as they were caught offside a whopping 10 times, per ESPN Stats and Info:

10 offsides in this game for Italy, the most of any team in a game this WC. Second is also Italy with 7 vs England. #WorldCup#ITAvsCRC

The Uruguay defense is there for the taking, and if Italy can maintain a consistent presence in the Uruguay half, they can keep the ball off the feet of Suarez.

Group E

France, Switzerland

France are not yet through to the round of 16 in the same way that Norwich were not yet relegated heading into the final day of the Premier League season. Yes, mathematically, Les Bleus still have some work to do, but at this point, it would take an act of God for them to miss out.

Ecuador are a team you don't want to sleep on, but France have been one of the best teams of the tournament so far. Still with a little bit of work to do, they shouldn't have their minds elsewhere and take their opponents lightly.

Switzerland looked bad against France. There's no two ways about it. But even the best teams have a bad day at the office sometimes. The Swiss are a bit lucky in that they have Honduras in their final match of the group stage.

Although the Hondurans will hunker down and kick Switzerland to no end, the Swiss should get the three points they need to advance. Even a draw will get them through if Ecuador lose to France.

Group F

Argentina, Nigeria

Dolores Ochoa/Associated Press

Lionel Messi's winner against Iran sent Argentina through. La Albiceleste can still play spoiler for Nigeria, though. The Super Eagles aren't safe yet, and a heavy loss to the Argentines could see them fall behind Iran.

The trouble for Iran is that they are meeting a Bosnia and Herzegovina side without a win. While the Dragons could pack it in, more than likely they won't want to leave their first World Cup with their tails tucked between their legs.

Edin Dzeko in particular should find some luck after having almost everything go wrong against Nigeria last Saturday.

If Bosnia and Herzegovina get the job done, Nigeria will be headed to the round of 16.

Group G

Germany, United States

Martin Rose/Getty Images

Unless they suffer a massive defeat on Thursday, Germany are through. Having a plus-four goal differential comes in handy at this stage of the tournament. They have one foot and three toes on their other foot in the door.

The bad news for the United States is that they let a place in the round of 16 slip right through their fingers with SilvestreVarela's 95th-minute winner. The good news is that they're still in a great position to advance. Paul Carr of ESPN Stats and Info calculates their chances of going on at 76 percent:

Portugal and Ghana still have a shot at going through. They need to win and make up a five-goal and two-goal difference, respectively, between themselves and the United States.

With the question marks surrounding Germany's defense, the Americans should be able to at least score enough to earn a draw with Die Mannschaft.

Group H

Belgium, Russia

Christopher Lee/Getty Images

With Divock Origi's winner in the 88th minute, Belgium booked their place in the round of 16. Although de Rode Duivels haven't looked like the team that most expected coming into the tournament, they've done enough in what is a weaker group.

With all due respect to South Korea, the final spot in Group H looks to be between Russia and Algeria, who meet on Thursday.

The Fennec Foxes surprised many with their 4-2 win against South Korea on Sunday. Many still believe Algeria to be the side in 2010 that played an ultra pragmatic, defensive style. This year's team couldn't be any different.

Although their attack is improved from four years ago, they'll be encountering a tough Russian side that really should've kept a clean sheet against South Korea and held Belgium scoreless for 88 minutes. Fabio Capello has sacrificed beauty for prudence.

The combination of Vasili Berezutski and Sergei Ignashevich should keep the Foxes at bay.

Russia's biggest problem will be scoring. Aleksandr Kokorin didn't play well against either Belgium or South Korea.

Don't be surprised to see this match finish 1-0 to Russia. They'll steal a goal early out of nothing and then back into their defensive shell.